A sheet conveying device included in an image forming apparatus is required to stack sheets aligned on a discharge tray for conveyance of the sheets with high stacking quality to the discharge tray in the case where the sheet conveying device conveys a sheet such as an original and a recording paper, which is processed after an image reading process or an image forming process in the image forming apparatus.
FIGS. 9A and 9B are explanatory views illustrating an exemplary conventional sheet conveying device A1 that degrades stacking quality. FIG. 9A is a schematic side view illustrating a discharged state of a sheet P conveyed to a discharge tray B4 viewed from an axial direction X of conveyance rollers B1 and B2. FIG. 9B is a schematic side view illustrating a conveying state of the sheet P viewed from a conveying direction Y of the sheet P.
The sheet conveying device A1 illustrated in FIGS. 9A and 9B includes a plurality of the first conveyance rollers B1 disposed coaxially with one another, and a plurality of second conveyance rollers B2 disposed coaxially with one another. The second conveyance rollers B2 face the respective plurality of first conveyance rollers B1. The sheet conveying device A1 conveys the sheet P while sandwiching the sheet P between the rotatably driven first conveyance rollers (drive rollers secured to a drive roller shaft E1) B1 and the second conveyance rollers (driven rollers secured to the driven roller shaft E2) B2. The first conveyance rollers B1 are rotatably driven while the second conveyance rollers B2 rotate in association with the rotation of the first conveyance roller B1.
This conventional sheet conveying device A1 easily causes inconvenience such as the following. When the sheet P is conveyed to one side Y1 in the conveying direction Y, the downstream side end (leading end) P1 is weighed down at one side Y1 in the conveying direction Y of the sheet P and the leading end P1 is brought in contact with the discharge tray B4 early. This early contact of the leading end P1 of the sheet P with the discharge tray B4 causes an upperstream side end (the rear end) P2, which is disposed at one side Y1 in the conveying direction Y, hooked into the second conveyance rollers B2 after the sheet P is conveyed (what is called rear end remaining (see a portion a in FIG. 9A)). Alternatively, the sheet P curled by a fixing process may degrade stacking quality.